A magnetic recording and reproducing system, including recording a signal on a magnetic recording medium by an inductive head and reproducing the signal by a magneto resistance head. The gap length of the inductive head is 0.3 m or less. The maximum particle diameter of ferromagnetic powder is from 1/10 to of the gap length, the minimum particle diameter of the powder is from 1/100 to of the gap length, and the thickness of a magnetic layer is from 1/10 to of the gap length. The average particle size of the powder is from 10 to 35 nm, the tabular ratio is from 2 to 6, the squareness ratio of in-plane of the magnetic layer is from 0.5 to 0.9 in the longitudinal direction, and from 0.2 to 0.6 in the thickness direction, and the thickness of the magnetic layer is from 0.01 to 0.2 m.